预混燃气射流火焰噪声与火焰稳定性

RELATIONSHIP BETWEEN THE SOUND EMISSION OF THE PREMIXED GAS JET FLAME AND FLAME STABILITY

本文通过视频信号与声频信号实验分析了燃气射流火焰的声发射特征。燃气火焰的声发射在出现上有其突发性，与火焰的不稳定工况有关。当气流速度使火焰面达到临界脱火状态时，声发射达到最大。初步分析表明，当气流速度达到可以使未燃混合气突入火焰面内使火焰发生微小爆炸，引致声发射在宏观上突然增加。本文分析对于通过声波监测火焰；预警脱火有一定作用。

Through the experimental analysis on the synchronous signal of audio and video of the premixed gas jet flame, the characteristic of the flame is studied. The sound emission of the flame appears a kind of outburst related to the stability of the flame. The sound pressure increased remarkably while the flame approach to the blow-off state. Analysis shows that the mixed gas intrudes into the hot production gas and the explosion inside increases the sound pressure of the emission. It is useful to the presentiment of the blow-off by acoustic detection.